The present invention relates generally to electronic meters and automatic meter reading, and more particularly to TCP/IP-enabled electronic meters for remote two-way access over local area networks and wide area networks.
The present invention relates to automatic meter reading (AMR) systems for use in automatically reading electrical energy and other utility meters (e.g., water and gas meters). The invention is more particularly intended for, although not limited to, use in an electronic meter. Further background information on electronic meters can be found in U.S. Pat. No. 5,548,527, Aug. 20, 1996, titled xe2x80x9cProgrammable Electrical Energy Meter Utilizing a Non-Volatile Memoryxe2x80x9d (assigned to ABB Power TandD Company Inc.) Further background on automatic meter reading systems can be found in U.S. Pat. No. 5,553,094, Sep. 3, 1996, titled xe2x80x9cRadio Communication Network for Remote Data Generating Stations.xe2x80x9d
The present invention, as discussed in greater detail below, involves the use of a TCP/IP protocol suite and a hypertext transfer protocol (HTTP) server. The terms xe2x80x9cHTTPxe2x80x9d and xe2x80x9cTCP/IPxe2x80x9d are well known in the networking and telecommunications arts. For example, TCP/IP refers to a well known set of protocols for linking dissimilar devices across networks. The invention also involves the use of a xe2x80x9cgatewayxe2x80x9d. A gateway is a node in a network that connects two otherwise incompatible networks. Gateways may perform code and protocol conversion processes. A xe2x80x9cprotocolxe2x80x9d is a set of rules or procedures relating to the format and timing of data transmissions between two devices. Protocols typically break a file into equal-size blocks or packets. These are sent and the receiving device uses a mathematical procedure to determine whether the block or packet was received accurately.
An electronic metering system in accordance with the present invention comprises a wide area network (WAN) operating in accordance with a TCP/IP protocol; a local area network (LAN) comprising a plurality of meters each of which includes meter electronics for measuring a prescribed quantity supplied by a utility and memory for storing measured data and meter control parameters; a gateway operatively coupled to the LAN and the WAN; and an HTTP server operatively coupled to the LAN and the gateway, whereby the WAN is provided remote access to the measured data and control parameters of the meters.
Presently preferred embodiments of the invention further include a CGI (common gateway interface) application coupled to the HTTP server for use in accessing the measured data. Alternatively, the inventive system may include a virtual machine coupled to the HTTP server for use in accessing the data.
The prescribed quantity is preferably electricity, water or gas.
The HTTP server and CGI application may be embedded in each of the meters or, alternatively, embedded in the gateway.
Other features of the present invention are disclosed below.